This invention relates to the manufacture of paint roller covers or other similar applicators from animal pelts or other like shrinkable material.
In the past, in manufacturing paint roller covers, the roller sleeve or cover had to practically approximate the outer diameter of the core about which the cover was to be placed. In this process, a machine would have a plurality of longitudinal very thin narrow blades which would embrace the core so as to force the core within the inside of the cover. Since the core was coated with an adhesive and then inserted into the sleeve, with the adhesive between the blades, serious problems arose in displacement and non-uniformity of the adhesive. The cover and core assembly then was subjected to an exterior pressure so as to adhere the cover to the core and the longitudinal blades then were withdrawn from between the cover and the core. Not only were there serious problems resulting from the non-uniformity of the adhesive between the cover and core, but air pockets between the cover and the surface of the core were created forming irregularities in the paint roller cover which would appear on the surface which was to be painted. These problems became serious because an animal pelt cover would be used in very fine painting projects. For simplicity purposes, throughout this disclosure, the cover for the core will always be referred to as sheepskin because it is a superior animal type pelt for use for such purposes.
The present invention has been designed so as to overcome these serious problems.
Therefore, a principal object of this invention is to provide a new and improved sheepskin paint roller cover.
In general, the method of the present invention involves the concept of shrinking, particularly heat shrinking, the sheepskin sleeve onto the internal core rather than clamping the sleeve onto the core as has heretofore been practiced in the past as described above. Sheepskin appears to be particularly responsive to shrinkage onto the internal core. In producing the roller cover of the present invention, the sleeve is formed with an inside diameter substantially larger than the outside diameter of the core. In addition, the shrinkage of the sleeve onto the core is accomplished by a steam heat. With the sleeve being substantially larger than the core, the longitudinal blades which grasp the core for insertion into the sleeve can be much thicker and a larger amount of adhesive can be placed therebetween to enhance a tighter bondage between the sleeve and the core. With the sleeve embraced about the core, the assembly then is subjected to steam heat for varying periods of time at varying pressures and temperature completely upon the quality and type of pelt in order to obtain the desired shrinking results. Several methods of treating the assembly with the steam heat have been attempted and each method seems to work to some extent. One process has been to subject the exterior of the assembly to a "steam stress" similar to steaming a pair of trousers in a laundry. A second process has been to insert a steam heat injector within the core of the assembly. A third process has been to insert the entire assembly into a steam chamber whereby the steam heat competely surrounds the assembly from the outside of the sleeve as well as the inside of the core. This latter process has proved very effective.
In steam shrinking the sheepskin pelt onto the core, it has to be necessary to prevent longitudinal shrinkage of the sheepskin pelt relative to the length of the interior core. Thus, the ends of the sheepskin cover are clamped to the ends of the core to prevent such longitudinal shrinking. One method simply has been to use such items as staples to penetrate both the sleeve and core to hold the sleeve longitudinally relative to the core. Another method which has proved very effective has been to make the sleeve slightly longer than the core so that as the sleeve shrinks, the overlapped portions also will shrink and actually physically grab the ends of the core to prevent the longitudinal shrinkage. In one form, the sleeve is made considerably longer than the core at least at one end thereof so that, after heat shrinking, the sleeve has an end radial portion overlapping the end of the core for painting adjoining corner surfaces.
Many advantages to this new and improved method are apparent from the above general description. For instance, the shrinking of the sleeve onto the core provides a much improved adhesion to make a much tighter fit onto the core. In addition, air bubbles which were present in rollers made by prior processes have been eliminated. Also, the shrinkage of the sheepskin pelt itself causes the hair of the pelt to come closer together to provide a much smoother and tighter matte for a much improved painting process.
In accordance with the exemplary embodiment of the present invention, a method of fabricating a paint roller cover or similar applicator from animal pelt, such as sheepskin or like shrinkable material, comprises the steps of cutting a predetermined size section from a portion of a sheepskin pelt and forming the section into a sleeve. The sleeve is formed by joining opposite edges, such as by stitches, with the skin side of the pelt facing outwardly so as not to interfere with the matte of the hair of the pelt. The sleeve then is inverted with the hair facing outwardly and the skin portion of the pelt forming the inside of the sleeve. A core is coated with an adhesive material and inserted into the sleeve which is of a substantially larger diameter than the core. The ends of the sleeve are clamped to the core either by staples or by overlapping the ends of the core and the assembly is subjected to steam heat by various methods, three of which have been described above. After a predetermined time, pressure and temperature, depending on the quality and type of animal pelt, the steam heat is cut off and a very tightly bonded uniform paint roller cover has been formed. The only remaining step is to trim the ends of the roller cover so as not to form loose hair which would accumulate paint and cause dripping. However, the overlapped portion of the sleeve at least at one end of the roller cover may be left in place for painting adjoining corner surfaces.
Lastly, it has been found that it is desirable to permit the roller cover which has already been subjected to the steam heat to remain in the chamber with the steam off for a very short period of time for curing purposes.
Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.